1*4882a593SmuzhiyunFrom f7b3134457e764badb5b24d6fcd1636d1950b1ef Mon Sep 17 00:00:00 2001 2*4882a593SmuzhiyunFrom: Catalin Marinas <catalin.marinas@arm.com> 3*4882a593SmuzhiyunDate: Tue, 23 Jul 2019 19:58:39 +0200 4*4882a593SmuzhiyunSubject: [PATCH] BACKPORT: arm64: Introduce prctl() options to control the 5*4882a593Smuzhiyun tagged user addresses ABI 6*4882a593Smuzhiyun 7*4882a593Smuzhiyun(Upstream commit 63f0c60379650d82250f22e4cf4137ef3dc4f43d). 8*4882a593Smuzhiyun 9*4882a593SmuzhiyunIt is not desirable to relax the ABI to allow tagged user addresses into 10*4882a593Smuzhiyunthe kernel indiscriminately. This patch introduces a prctl() interface 11*4882a593Smuzhiyunfor enabling or disabling the tagged ABI with a global sysctl control 12*4882a593Smuzhiyunfor preventing applications from enabling the relaxed ABI (meant for 13*4882a593Smuzhiyuntesting user-space prctl() return error checking without reconfiguring 14*4882a593Smuzhiyunthe kernel). The ABI properties are inherited by threads of the same 15*4882a593Smuzhiyunapplication and fork()'ed children but cleared on execve(). A Kconfig 16*4882a593Smuzhiyunoption allows the overall disabling of the relaxed ABI. 17*4882a593Smuzhiyun 18*4882a593SmuzhiyunThe PR_SET_TAGGED_ADDR_CTRL will be expanded in the future to handle 19*4882a593SmuzhiyunMTE-specific settings like imprecise vs precise exceptions. 20*4882a593Smuzhiyun 21*4882a593SmuzhiyunReviewed-by: Kees Cook <keescook@chromium.org> 22*4882a593SmuzhiyunSigned-off-by: Catalin Marinas <catalin.marinas@arm.com> 23*4882a593SmuzhiyunSigned-off-by: Andrey Konovalov <andreyknvl@google.com> 24*4882a593SmuzhiyunSigned-off-by: Will Deacon <will@kernel.org> 25*4882a593SmuzhiyunChange-Id: I2d52c5589b05415faab315c116245f1058d64750 26*4882a593SmuzhiyunSigned-off-by: Andrey Konovalov <andreyknvl@google.com> 27*4882a593SmuzhiyunBug: 135692346 28*4882a593Smuzhiyun(cherry picked from commit f077ee260964eb925a593dcf30553432b3243ac8) 29*4882a593Smuzhiyun 30*4882a593SmuzhiyunConflicts: 31*4882a593Smuzhiyun arch/arm64/Kconfig 32*4882a593Smuzhiyun arch/arm64/include/asm/processor.h 33*4882a593Smuzhiyun arch/arm64/include/asm/thread_info.h 34*4882a593Smuzhiyun arch/arm64/include/asm/uaccess.h 35*4882a593Smuzhiyun arch/arm64/kernel/process.c 36*4882a593Smuzhiyun include/uapi/linux/prctl.h 37*4882a593Smuzhiyun kernel/sys.c 38*4882a593Smuzhiyun 39*4882a593SmuzhiyunOnly port definations to pass newest glibc compiling. 40*4882a593Smuzhiyun 41*4882a593SmuzhiyunSigned-off-by: Jeffy Chen <jeffy.chen@rock-chips.com> 42*4882a593Smuzhiyun--- 43*4882a593Smuzhiyun include/uapi/linux/prctl.h | 5 +++++ 44*4882a593Smuzhiyun 1 file changed, 5 insertions(+) 45*4882a593Smuzhiyun 46*4882a593Smuzhiyundiff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h 47*4882a593Smuzhiyunindex 4d05aad2e4c5..eabab9f1ee38 100644 48*4882a593Smuzhiyun--- a/include/uapi/linux/prctl.h 49*4882a593Smuzhiyun+++ b/include/uapi/linux/prctl.h 50*4882a593Smuzhiyun@@ -219,4 +219,9 @@ struct prctl_mm_map { 51*4882a593Smuzhiyun # define PR_SPEC_DISABLE (1UL << 2) 52*4882a593Smuzhiyun # define PR_SPEC_FORCE_DISABLE (1UL << 3) 53*4882a593Smuzhiyun 54*4882a593Smuzhiyun+/* Tagged user address controls for arm64 */ 55*4882a593Smuzhiyun+#define PR_SET_TAGGED_ADDR_CTRL 55 56*4882a593Smuzhiyun+#define PR_GET_TAGGED_ADDR_CTRL 56 57*4882a593Smuzhiyun+# define PR_TAGGED_ADDR_ENABLE (1UL << 0) 58*4882a593Smuzhiyun+ 59*4882a593Smuzhiyun #endif /* _LINUX_PRCTL_H */ 60*4882a593Smuzhiyun-- 61*4882a593Smuzhiyun2.20.1 62*4882a593Smuzhiyun 63